1. Field of the Invention
The present invention relates generally to transmission and reception of signals in a wireless communication system, and more particularly, to a method and an apparatus for providing an implicit mapping between DeModulation Reference Signals (DMRS) and control channels.
2. Description of the Related Art
In 3rd Generation Partnership Project (3GPP) Long-Term Evolution (LTE) releases 8 to 10, a control channel is transmitted in the first a few Orthogonal Frequency Division Multiplexing (OFDM) symbols of a subframe. As the system continues to evolve and more users are to be scheduled in the same subframe, the legacy control channel capacity will bottleneck for further performance enhancement. To enhance the capacity of control channel, an enhanced Control CHannel (eCCH) is designed using remaining OFDM symbols in a subframe, which was previously allocated for data transmission in the legacy systems.
Multiple eCCHs for the same or multiple User Equipments (UEs) can be multiplexed in one resource block. The multiple eCCH may have different reference signals on different antenna ports for demodulation. Therefore, in order to recover the information transmitted on an eCCH, a user must acquire the mapping between the eCCH and the reference signals before demodulation.